Exemestane
Ancillaries & recoveryAlso known as Aromasin
A steroidal aromatase inhibitor that inactivates the enzyme permanently rather than blocking it reversibly.
How it works
A substrate analogue that binds aromatase irreversibly, so the enzyme has to be resynthesised before conversion resumes. That is why its effect outlasts its plasma half-life, and why plasma concentration is a poor guide to how much suppression is still in effect.
In the body
Shape of a single dose, modelled as one compartment with first-order absorption. The peak is normalised to 100% because bioavailability and volume of distribution are not published for most of these compounds.
About 27 hours in plasma at the 25 mg dose. The curve the app draws is the plasma curve and understates the duration of effect: the enzyme is inactivated irreversibly, so suppression persists past the point the drug has gone.
Your notes
Doses
25 mg daily, the approved breast cancer dose. Absorption improves substantially with food.
6.25 to 12.5 mg, a quarter to a half tablet. Preferred by some over anastrozole for a smaller effect on lipids, though the comparison is not established in men.
Side effects
- Joint pain, as with any aromatase inhibitor pushed too far
- Hot flushes and sweating
- Fatigue and low mood
- Mildly androgenic in its own right, being a steroidal molecule
- Monitor: oestradiol by sensitive assay
Cautions
- Taking a second aromatase inhibitor at the same time
- Running it on a compound that does not aromatise
- Pregnancy
Status
Prescription-only. Approved for breast cancer, not for oestrogen management in men. Banned in sport at all times.
Sources
Reference information for personal record-keeping. Not medical advice, and not a recommendation to use any of these compounds.